Petro Poroshenko, has vowed not to give up control of Crimea to Russia in his first address as President of Ukraine.

The billionaire “Chocolate King” was inaugurated on Saturday and set out his plans for quelling violence in the east of the country, where hundreds have died in bloody clashes between the army and pro-Russian rebels.

In his first address, Mr Poroshenko promised amnesty “for those who do not have blood on their hands” and called for dialogue with “peaceful citizens” in the east.

“I am calling on everyone who has taken arms in their hands — please lay down your arms,” he said, according to a translator.

He had already received a friendly welcome from Western leaders and vowed to work with the Russian President to “end the bloodshed” in eastern Ukraine.

Despite the talks, the Ukrainian President vowed not to accept Russia's annexation of Crimea.

“Crimea was, is and will be Ukrainian. There will be no trade-off,” he said.

Ukraine's President-elect Petro Poroshenko (left) and Russian President Vladimir Putin during an international D-Day commemoration ceremony
Russia annexed the peninsula in march and the subsequent secession referendum was regarded as illegitimate by Kiev and some Western countries.

Mr Putin has denied allegations that Russia has fomented the rebellion in the east, and he insisted that the Government needs to speak directly to rebels.

Mr Poroshenko also called for early regional elections and promised increased powers for local governments but rejected calls for the federalisation of Ukraine.

He insisted that Ukrainian would remain the only state language but promised “new opportunities for the Russian language,” without elaborating on specifics.

The task is a far cry from the manufacturing business that made the 48-year-old’s estimated $1.6 billion (£950 million) fortune.

He started his chocolate manufacturing business by importing cocoa beans into the Soviet Union in 1991 and eventually started Roshen, the foundation of a business empire that now includes ship-building and one of the country's most influential TV stations.

Unlike many other Ukrainian billionaires, Mr Poroshenko did not make his money in murky post-Soviet privatisations, boosting his reputation as a “good tycoon”.

His political career began in 1998 and he went on to hold several positions in the former President’s Party of Regions but threw his weight behind 2004’s anti-corruption Orange Revolution.

Mr Poroshenko faced allegations of corruption himself when he stepped down as head of national security amid rumours he had used his influence to benefit another tycoon.

He later returned to serve as Foreign Minister, and briefly as economics minister after Mr Yanukovych came to power in 2010 and surprised the public last year by allying himself early with the pro-European Maidan protest movement in Kiev that caused his former leader’s downfall.

He then allied with a potential rival, former boxing champion Vitali Klitschko, and endorsed him for Kiev mayor as Mr Klitschko supported him for president.

Mr Poroshenko supports signing an association agreement with the European Union, but has spoken against holding a vote on whether Ukraine should seek Nato membership.

Relations with Moscow should be good but equal and should not undermine Ukrainians' desire for closer ties with the European Union, he says.

For now, his priority will be putting a stop to the violence in the east that has killed more than 200 people in recent weeks, according to Government estimates.

Ukraine's cash-strapped Government, desperate to receive the full $17 billion (£10 billion) loan package promised by the International Monetary Fund, will have to undertake serious constitutional reforms early in his tenure as President.

Mr Poroshenko also faces a major hurdle in encouraging Parliament to agree to hold elections this year instead of in 2017 as scheduled.

If he fails, he could face the same challenges as the Orange Revolution government, which took two years to hold parliamentary elections.